Reversible tool drive

ABSTRACT

THIS INVENTION RELATES TO A SOCKET WRENCH DRIVE CHARACTERIZED BY A REVERSIBLE ONE-WAY CLUTCH WHEREIN A ROTATABLE CYLINDRICAL MEMBER IS RELEASABLY LOCKED WITH A CENTRAL CAVITY IN THE HEAD FOR CONJOINT ROTATION BY ROLLERS WEDGED BETWEEN THE CYLINDRICAL MEMBER AND A CAM SURFACE AT THE END OF A RADIAL RECESS OPENING ONTO SAID CAVITY. SPRING ELEMENTS ARE RELEASABLY HELD AGAINST THE ROLLERS BY A CONTROL RING TO BIAS SAME IN EITHER A &#34;FORWARD&#34; OR &#34;REVERSE&#34; POSITION.

1971 w. SEABLOM REVERSIBLE TOOL DRIVE Filed July 24, 197 0 INVENTOR.WENDELL SEABLOM vwvs ATTORNEYS United States Patent 3,621,739 REVERSIBLETUOlL DRIVE Wendell Seablom, 316 S. 138th St, Tacoma, Wash. 98444 FiledJuly 24, 1970, Ser. N0. 57,950 Int. Cl. 1325]) 13/00, 13/46 US. Cl.81--59.1 13 Claims ABSTRACT OF THE DISCLOSURE Socket wrench drives ofone type or another are notoriously old in the art, most of themutilizing some form of the ratchet-and-pawl principle. While certainlyquite simple in construction, this type of wrench has the disadvantageof having to be reversed a discrete angle to engage the next notch ofthe ratchet-and-pawl mechanism. Also it is rather susceptible to wearduring heavy use such as it would ordinarily be subjected to in a shopor garage. Other types are less sensitive to wear on the Working partsbut, at the same time, they involve complex and costly one-way clutchesthat make the unit expensive as well as subject to malfunction for otherreasons than wear.

Head size is another disadvantage of the prior art socket wrenches inthat many are either too thick or overly wide to fit into hard to reachplaces. Ideally, one would like to be able to fit a socket wrench intoall places where an end wrench would fit and, since this is virtuallyimpossible due to the space required for the operating mechanism, thebest that can be done is to approach this condition.

The socket wrench drive presently disclosed and claimed has theadvantage of being continuously engageable over the entire 360 ofrotation. This means that in hard to reach places a fastener can beturned very small increments on each stroke or that full advantage maybe made of the space available without having to reverse the stroke adiscrete engaging notch of the wrench drive.

The socket wrench drive of the instant invention has the furtheradvantage of extreme simplicity Without sacrificing its functionality.The parts are few in number and quite simple to fabricate; yet, theirdesign is such that they are extremely rugged. Case-hardened steelrollers wedged between cam surfaces at the bottom of the recesses andthe similarly hardened surface of the central rotating member bear thetorque loads with little wear. If parts need to be replaced or repairsmade, removal of the cover enables one to completely disassemble theunit with only a small screwdriver. Even compact versions of the unithaving rollers of minimal diameter and a thin-walled case bordering thecam-surfaced recesses will ordinarily withstand torque loads severaltimes greater than that which will shear off the bolt or other fastenerto which the tool is applied.

The reversing mechanism is simplicity itself in that pairs of coilsprings engage opposite sides of each roller and, depending upon theposition of the control ring, bias the rollers toward one side of thecam surface or the other. These springs carry none of the torque loadand, for this reason, are very light. The non-biasing springs cooperatewith the control ring to hold it in either its forward or reverseposition.

3,621,739 Patented Nov. 23, 1971 It is, therefore, the principal objectof the present inven tion to provide a novel and improved socket wrenchdrive.

A second objective of the invention forming the subject matter hereof isthe provision of a socket wrench having a reversible one-way clutch ofunique design.

Another object of the invention herein disclosed and claimed is theprovision of a one-way clutch mechanism based upon a wedged-rollerlocking arrangement whereby the clutch is continuously engageable overthe entire 360 of rotation.

Still another objective is to provide a socket wrench drive wherein theone-way clutch is shifted by a simplified forward-reverse actuator.

An additional object is the provision of a socket wrench drive thatlocks more securely on the work piece as the torque load increases.

Further objects of the invention are to provide a socket wrench drivethat is easy to operate, rugged, wear-resistant, compact, reliable,simple to service and repair, versatile and even somewhat decorative.

Other objects will be in part apparent and in part pointed outspecifically hereinafter in connection with the description of thedrawings that follows, and in which:

FIG. 1 is a side elevation view of a socket wrench employing the hereindescribed reversible drive;

FIG. 2 is a fragmentary section to an enlarged scale taken along line 22of FIG. 1 showing the rollers in a position for tightening a right-handthread fastener;

FIG. 3 is a view substantially identical to FIG. 2 except that thecontrol ring is shown in a position to shift the rollers into a positionfor tightening a left-hand thread fastener;

FIG. 4 is a view substantially identical to FIG. 2 except that thecontrol ring is shown in. a position to shift the rollers into acentered or neutral position; and

FIG. 5 is a fragmentary section view taken along line 5-5 of FIG. 4 withthe cover plate shown in position.

Referring next to the drawings for a detailed description of the presentinvention and, initially, to FIG. 1 for this purpose, reference numeral10 has been chosen to broadly designate the socket wrench drive in itsentirety while numeral 12 refers specifically to the handle thereof andnumeral 14 to the head on one end of said handle. The head 14 has a toolholder 16 of rectangular cross section projecting through an essentiallyflat planar cover plate 18 thereof, while the control ring 20 whichfunctions as the reversing actuator completely encircles the top portionof the head 14.

The handle 12 in the manner of most socket wrench drives is straight andincludes a checkered end portion 26 to provide a better hand grip. Thehead 14, on the other hand, comprises a shallow generally cylindricalenlargement with tool holder 16 projecting upwardly from the centerthereof and through cover plate 18.

Next, with reference to FIGS. 2-5, inclusive, the details of thereversible one-way clutch assembly that has been designated broadly byreference numeral 30 and which is housed in the head 14 will be setforth in detail. The head contains a centrally-located generallycylindrical cavity 32 having, in the particular form shown, threeequiangularly-spaced radial recesses 34 radiating therefrom thatterminate in concave cam surfaces 36. This central cavity is terminatedat the bottom by the inside face 24 of the head 14 and is open at thetop of head 14 and adapted to receive cover plate 18.

Seated within the bottom of this cavity 32 is a rotating element 40which includes a cylindrical portion 42 freely rotatable within saidcavity and having the tool holder 16 projecting axially therefrom as anintegral part thereof. Rotating element 40 is partially held in positionby a cylindrical axial extension 43 on the bottom thereof which fitsinto guide hole 45 bored in the inside face 24 of the central cavity.Cylindrical portion 42 of the rotating element 40 cooperates withcylindrical rollers 44 seated in the bottom of the radial recesses 34and the cam surfaces 36 at the base of the latter to define the one-wayclutch 30, the operation of which will be described in detail presently.

Surrounding the central cavity is the upstanding annular side wall 46 ofthe head 14. The cover plate 18 with central aperture 50 fits onto thetop of this side wall and is held in place by machine screws 52. Theoutside of side wall 46 is reduced in diameter around its top portionleaving a flange 54 formed by the bottom portion of head 14. Controlring 20 then encircles this outside wall, rests on flange 54, and isheld in place by cover plate 18 which is sized large enough to extendout over the control ring.

Each of the cylindrical rollers 44 seated in the radial recesses areacted upon by a pair of biasing elements which operate on substantiallyopposite sides thereof and tend to urge the rollers in oppositedirections around the rotating element 40. In the particular embodimentshown these biasing elements are coil springs 56 which fit into passages58 drilled through the head side wall which are equally spaced aroundthe central cavity and essentially parallel to lines tangent to thecylindrical portion of rotating element 40. The passages thus formopenings from the radial recesses 34 which terminate in holes 60 in theoutside of side wall 46. The coil springs are fitted on the outside endwith a bearing cap 62 and are inserted into the passages so that theuncovered end bears against the rollers 44. The springs are of a lengthwhich causes the rollers to be equally biased on both sides when thebearing cap of each spring is flush with the outside of the side wall.

Control ring 20 is constructed with its inside surface having threeequiangularly-spaced pockets 64 adapted to register with correspondingholes 60 of each roller-biasing mechanism and relieve three of thecorresponding biasing springs when so registered. It will be noted thatthe control ring is limited in its rotational movement by the stoppingaction of the following edges 65 of the pockets acting against thebearing caps 62 which protrude into the pockets. When the control ringis in a position so that the pockets are not aligned with any of theholes 60, the bearing caps 62 are all held inside the periphery of thehead side wall and each pair of springs pushes against the rollers withequal force thereby tending to hold them in a neutral position as shownin FIG. 4. A shift in the control ring from the neutral position of FIG.4 into one or the other of the actuated positions of FIGS. 2 or 3 willrelieve the lead element of each pair of springs while causing thefollowing element to push the roller ahead thereof inwardly along thecam surface to a position where it begins to wedge between the lattersurface and the cylindrical bearing surface 42 of the rotating element.Once this occurs, the one-way clutch 30 engages to lock the rotatingelement 40 within the head 14 for conjoint rotation in the directionopposite to that in which the rollers are are biased, i.e., in thedirection of the arrows in FIGS. 2 and 3. In other words, in FIG. 2, thetool holder (not shown), which projects upwardly, will presumably befitted with a socket that is, in turn, engaged with a work piece whichresists rotation; therefore, counter-clockwise motion of the head 14will act to roll the rollers 44 counterclockwise also and they will tendto clamp further up the cam surface and wedge even more tightly againstthe rotating element. The opposite is, of course, true of the operationof the one-way clutch in the reverse position of FIG. 3.

Again, with reference to FIG. 2, when the head is turned clockwise, theaction of the rollers will be such as to roll down the cam surfacetoward the neutral position of FIG. 4 thus withdrawing the wedge formedthereby and releasing the rotating element 40 to remain in fixedposition while the head 14 turns, as aforesaid, clockwise relativethereto.

The cam surfaces 36 must, obviously, be concave and have a radius ofcurvature substantially greater than that of the rollers 44. Thesesurfaces are preferably symmetrical on opposite sides of a radial linepassing through the midpoint thereof. Most important, of course, is thatthe neutral area 66 of the cam surface located approximately midwaybetween the ends thereof be spaced away from the bearing surface 42 ofthe rotating element a distance greater than the diameter of the roller44 that moves therebetween. Of equal importance is that the end portions68 of the cam surface on opposite sides of the neutral area 66 graduallyapproach the bearing surface 42 of the rotating element until thedistance separating the latter is less than the diameter of the roller44. A cylindrical cam surface works quite well for the purposes of thepresent invention although the preferred form thereof is to make bothend portions 68 thereof cylindrical surfaces of essentially the sameradius of curvature but separate them by a flattened neutral area of agreater radius of curvature or even a planar surface.

As illustrated, the clutch subassembly 30 includes threeradially-disposed recesses located apart and this is the preferrednumber; however, it is obvious that more than three can be used althoughno particular advantage exists in so doing and the unit becomes morecomplicated and expensive. On the other hand, two diametricallyplacedrecesses could probably be made to workas, for that matter, could asingle one; however, in so doing, a portion of the bearing surface ofthe rotating element would have to bear directly against the wall of thecentral cavity which is not designed to resist the type of slidingcontact occasioned by each retraction stroke as opposed to the workstroke where little relative motion takes place.

Another rather obvious modification is to substitute balls for therollers 44. Here again, while this would surely work, to do so resultsin a concentration of the torque loads at three points rather thanspreading these loads out along lines extending the length of eachroller as has been done here. Accordingly, the roller construction shownis preferred.

Furthermore, the biasing elements can take many alternative forms, suchas leaf springs, torsion rods, or even coil springs under tension,without departing from the basic teaching of the present invention. Alsothe disclosed drive could be made non-reversible, and therebysimplified, by deleting all of the biasing elements on correspondingsides of each roller. While all of these modifications are possible andmay be practical in certain applications, the embodiment shown anddescribed is the preferred one.

I claim:

1. The reversible tool drive which comprises: handleforming means; ahead rigidly connected to the handleforming means for rotationtherewith, said head including a tool-receiving cavity in one facethereof adapted to accept the cylindrical body portion of a tool forrotation therein, at least three concavely arcuate cam-forming recessesopening radially inward onto the cavity, an outwardly-facinggenerally-cylindrical control ring track encircling the recesses andcavity, and chordal biasing element passages extending from oppositesides of each camforming recess onto the adjacent surface of the controlring track; a tool having a cylindrical body portion mounted in thetool-receiving cavity for rotational movement in either direction aboutits own axis, said tool having means projecting axially from itscylindrical portion adapted for releasable connection to a Work piece oranother tool; roller means mounted in each recess in tangential contactwith the arcuate surface of the latter and the cylindrical body of thetool, said roller means c0- operating with their respective arcuate camsurfaces to define a centrally located neutral position adapted topermit free rotation of the tool means in either direction, and saidroller means cooperating with their respective cam surfaces on bothsides of said neutral position to define a pair of operative positions,one of said operative positions permitting free relative clockwiserotation of said tool while locking the latter against relativecounterclockwise rotation, and the other of said operative positionspermitting free relative counterclockwise rotation thereof while lockingsame against relative clockwise rotation; shiftable spring-biaseddetents mounted in each chordal passage bearing against opposite sidesof their respective rollers, opposed pairs of said detents cooperatingwith one another in one position to exert an unequal bias on each of therollers in a clockwise direction and in a second position an unequalbias on each of said rollers in a counterclockwise direction, all of thedetents on one side of their respective rollers defining a first setthereof while the detents on the other side define a second set; and,means comprising a control ring mounted on the cylindrical track forboth clockwise and counterclockwise rotation relative thereto, said ringincluding on the inner surface thereof first and second sets of camsurfaces; said first set of cam surfaces being positioned and adapted inone operative position of said ring to simultaneously actuate the firstof detents so as to bias the rollers clockwise and said first set of camsurfaces being positioned and adapted in a second operative position ofsaid ring to simultaneously actuate the second set of detents so as tobias said rollers counterclockwise and said second set of cam surfacesin the first operative position of said ring being positioned andadapted to cooperate with the first set of cam surfaces so as tosimultaneously release said second set of detents into their deactivatedpositions and in the second operative position of said ring to similarlyrelease the first set of detents into their deactivated positions.

2. The reversible tool drive as set forth in claim 1 in which: acentrally-apertured cover plate is removably attached to the head and issized to cooperate therewith so as to hold the control ring, detents,rollers and tool means in assembled relation.

3. The reversible tool drive as set forth in claim 1 in which: therollers are cylindrical.

4. The reversible tool drive as set forth in claim 1 in which: thearcuate cam-forming recesses are equiangularly-spaced around the cavity.

5. The reversible tool drive as set forth in claim 1 in which: thearcuate cam-forming recesses are substantially cylindrical.

6. The reversible tool drive as set forth in claim 1 in which: there arethree concavely arcuate cam-forming recessess opening inward onto thecavity.

7. The reversible tool drive as set forth in claim 1 in which: the camsurfaces in the inner surface of the control ring are adapted andlocated whereby the control ring can be rotated to a position holdingboth sets of detents in an actuated position to exert substantiallyequal forces on each side of the rollers thereby allowing the tool meansto freely rotate in either direction.

8. The reversible tool drive as set forth in claim 1 in which: thespring-biased detents each include a coil spring having a bearingsurface on each end with one end in engagement with the roller and theother end projecting sufficiently outwardly in the said chordal passageto engage the said first set of cam surfaces.

9. The reversible tool drive as set forth in claim 1 in which: thespring-biased detents each include a coil spring in engagement with theroller and a pin projecting sufficiently outwardly in the said chordalpassage to engage the said first set of cam surfaces.

10. The reversible tool drive as set forth in claim 11 in which: the setof detents in the deactivated position cooperative with the second setof cam surfaces to form a stop limiting the rotation of the controlring.

11. The reversible tool drive as set forth in claim 1 in which: the axesof the chordal biasing element passages extending from opposite sides ofeach cam-forming recess are substantially collinear along a line passingthrough the roller and parallel to a line tangent to the cylindricalbody portion of the tool means.

T2. The reversible tool drive as set forth in claim 1 in which: the axesof the chordal biasing element passages extending from opposite sides ofeach cam-forming recess are substantially collinear along a line passingthrough the roller and perpendicular to a line through the axis ofrotation of the tool means and the center of the roller when said rolleris in the centrally-located neutral position.

13. The reversible tool drive as set forth in claim 1 in which: the axesof the chordal biasing element passages extending from opposite sides ofeach cam-forming recess are substantiallly collinear along a linepassing through the center of the roller when said roller is in thecentrally located neutral position and perpendiculatr to a line throughthe axis of rotation of the tool mean and the center of the roller whensaid roller is in said centrallylocated neutral position.

References Cited UNITED STATES PATENTS 2,119,622 6/1938 Freber 8159.1 X3,362,267 1/1968 Rozmus 81-59.1 2,584,256 2/1952 Brown 81-591 X FOREIGNPATENTS 1,121,260 2/1956 France 19212 B JAMES L. JONES, Jr., PrimaryExaminer US. Cl. X.R.

